Auxiliary contact for calipers



Nov. 14, 1950 4 J. F. GALLUP, SR 2, 2

AUXILIARY CONTACT FOR CALIPERS Filed Sept. 26. 1945 2 Sheets-Sheet l Nov. 14, 1950 J. F. GALLUP, SR 2,529,931

AUXILIARY CONTACT FOR CALIPERS Filed Sept. 26, 1945 2 Sheets-Sheet 2 /0 2 Inventor Jfizz iyizzzp jn 4/ 9 By m Patented Nov, 14, 1950 UNITED STATES PATENT OFFICE...

AUXILIARY CONTACT FOR CALIPERS John F; Gallup, Sr., Newington, Conn.

Application September 26, 1945, Serial No. 618,648

- 3 Claims.

This invention relates to auxiliary contacts for Vernier calipers, by means of which the calipers are adapted for special work, such as measuring the diameter of a piece of work at internal or external chamfers, the gear root of internal or external gears, the diameter within external or internal grooves, etc. I

The present invention comprehends the provision of readily attachable and removable auxiliary contacts for the fixed and adjustable main contacts of ordinary Vernier calipers, and an important object of the invention is to provide auxiliary contacts of thiskind which are simple in construction, efiicient in use, and easy to apply or remove.

The exact nature of the present invention will become apparent from the following description when'considered in connection with the accompanying drawings, in which:

Figure 1 is a side elevational view of Vernier calipers equipped with auxiliary contacts constructed in accordance with the present invention.

Figure 2 is an enlarged section taken on line 22- of Figure 1.

Figure 3 is a section taken on line 33 of Figure 2.

Figure 4 is a perspective view of the clamp forming part of the construction shown in Figures 2 and 3.

Figure 5 is a fragmentary view illustrating another form of auxiliary contacts applied to the main contacts of Vernier calipers.

Figure 6 is a section taken on line 66 of Figure 5, and illustrating use of the contacts in measuring the gear root of an internal gear.

Figure 7 is a-view similar to Figure 6 illustrating use of the contacts in measuring the gear root of an external gear.

Figure 8 is an enlarged perspective view of one of the auxiliary contacts shown in Figure 5.

Figure 9 is a view som'ewhatsimilar to Figure 5 showing a still further form of auxiliary contacts and illustrating their use in measuring the diameter of a piece of work within an external groove.

Figure 10 is a perspective view of one of the auxiliary contacts shown in Figure 9.

Figure 11 is a view similar to Figure 10 illustrating a modification of the contacts shown in Figures 9 and 10 for use in measuring the diameter of a piece of work within an internal groove of the latter.

Referring in detail to the drawings, the auxiliary contacts of the present invention are adapted for attachment to the main contacts of Vernier calipers of conventional construction including a beam 5 having a fixed lateral contact 5 atone end and including an adjustable contact I mov able on the beam 5 and securable in adjusted positions by a set screw 8. As the construction and manner of use of these conventional calipers are well known in the art, more detailed description thereof is deemed unnecessary herein, except to point out that the inner edge portions 8 of the contacts 5 and 1 constitute straight edges.

In accordance with the present invention, similar auxiliary contacts '0 are provided for the main contacts 6 and 1 of the calipers.- Each auxiliary contact comprises a shank 9 and a work-contact ing terminal Ill on one end of said shank. The shank 9 has a straight longitudinal outer edge I I flatly engaged with the straight edge portion 8 of the associated main contact 6 or 1, and provided with a slot [2 which extends inwardly from its inner edge. A clamp is provided for securing the auxiliary contact to the associated main contact of the calipers, and said clamp preferably com: prises a U-shaped yoke I 3 which embraces the associated main and auxiliary contacts and has a cross-pin M which is engaged in the slot l Z of the auxiliary contacts. The clamp further inf cludes a set screw I5 which is threaded through the outer portion of the yoke I3 and impinges against the outer edge of the main contact to removably secure the auxiliary contact in place upon the associated main contact of the calipers.

In the embodiment of Figure 1, the work-contacting terminal is of V-shape and has beveled side edges l6 so that the inner beveled edge may contact the external chamfer I! of a piece of work l8, as indicated by dotted lines in Figure 1, while the outer beveled edge may contact the internal'chamfer [9 of a piece of work, as shown by full lines in Figure l. The shank 9 preferably has a lateral enlargement 20' which provides a shoulder 2| that abuts the free outer end of the associated main contact of the calipers to more effectively fix the auxiliary contact in place.

In use, the calipers are employed in the usual way except that the auxiliary contacts are used to contact the work instead of the regular main contacts of the calipers.

In the embodiment of Figures 5 to 7, inclusive, the auxiliary contacts C have shanks 9' whose work-contacting terminals I0 have straight or parallel beveled side edges I6. These auxiliary contacts are specially adapted for use when measuring the gear root of internal or external gears, as illustrated respectively in Figures 6 and '7. When. measuring the gear root of an internal gear,

the outer edges of the auxiliary contacts are employed as shown in Figure 6, while the inner edges of said auxiliary contacts are used when measuring the gear root of an external gear, as shown in Figure 7. Otherwise, the construction of Figure 5 is similar to that of Figure 1 and remaining like parts of both forms are indicated by similar reference characters. The same clamps may be used for any desired set of contacts.

In the embodiment shown in Figures 9 and 10, each auxiliary contact 0 includes a shank 9 provided with an extension 22 on which is provided the inwardly directed work-contacting terminal I0 As shown in Figure 9, this type of auxiliary contact is adapted for use in measuring the diameter of a piece of work ['8 within an external groove 23 of the latter. Remaining elements of this construction are similar to the embodiment of Figure 1 and are indicated by simi-' lar reference characters.

In order to measure the diameter of a piece of Work within an internal groove of the latter, auxiliary contacts may be used of the form'shown in Figure 11'. These contacts are identically the same as thoseshown in Figures 9 and 10, except that the work-contacting terminal I6 is directed outwardly instead. of inwardly. Remaining features of the contacts C are similar to those of contact C and are indicated by similar reference characters.

From. the foregoing description, it is believed that the construction, advantages and manner of use of the auxiliary contacts forming part of the present invention will be readily understood and appreciated by those skilled inthe art. Obviously, by modifying the auxiliary contacts to provide them With the desired form of work-contacting terminals, the Vernier calipers may be adapted for many kinds of special work in a ready and convenient manner. The auxiliary contacts will be provided in pairs and so constructed that any pair may be applied to the calipers by the use of the. same clamps. By simply loosening the set screws 15, the auxiliary contacts may .be readily removed from the. calipers when not required for use or when changing from one kind of auxiliary contacts to another.

What Iclaim is:

1. In combination with calipers including a beam having a lateral fixed main contact at one end and a second coacting adjustable main contact movable on the beam, said main contacts having inner straight edge portions, an auxiliary contact for each of said main contacts comprising av shank and a Work-contacting terminal on one end of said shank, said shank having a straight longitudinal outer edge flatly engageable with the inner straight edge portion of the associated main contact-and provided with a transverse slot having an open end at the inner edge of said shank, and a screw clamp for securing each auxiliary con-tact to the associated main contact, said clamp comprising a U-shaped yoke embracmg the associated main and auxiliary contacts and having a cross-pin engaged in the slot of said auxiliary contact to removably connect the latter to the clamp, and a set screw threaded through the outer portion of the yoke and impinging against the outer edge of said main contact.

2. In combination With calipers including a beam having a lateral fixed main contact at one end and a second coacting adjustable main contact movable on the beam, said main contacts having inner straight edge portions, an auxiliary contact for each of said main contacts comprising a shank and a V-shaped work-contacting terminal integral with and extending from one end of said shank longitudinally of the latter, said shank having a straight longitudinal outer edge flatly engageable with the straight edge portion of the associated main contact and provided with a transverse slot having an open end at the inner edge of said shank, and a clamp having means cooperating with said slot for securing the auxiliary contact to the associated main. contact, the Work-contacting terminal of each auxiliary contact having beveled V-shaped side edges to adapt the auxiliary contacts for use in. measuring the diameter of a piece of work at internal or external chamfers.

3. In combination With calipers including a beam having a lateral fixed main contact at one end and a second coacting adjustable main contact movable on the beam, said main contacts having inner straight edge portions, an auxiliary contact for each of s aidmain'contacts compris ing a shank and a work-contacting terminal on one end of said shank, said shank having, a straight longitudinal outer edge flatly engageable with the straight edge portion of the associated main contact and provided with a transverse slot having an open end at the in,- ner edge of said shank, and a clamp having means cooperating with said slot for securing the auxiliary contact. to the associated main contact, said work-contacting terminal having parallel beveled V-shaped opposite side edges disposed at right angles to the beam respectively for use in measuring the gear root of internal o external ears.

JOHN F. GALLUP, SR.

REFERENCES CITED- The following references are of record in the file of this patent:

UNITED STATES PATENTS 

